Calender, especially for paper satinizing



Jan. 23, 1968 G. MULLER CALENDER, ESPECIALLY FOR PAPER SATINIZING FiledDec. 16, 1964 II II United States Patent i'ifiti iAd Patented Jan. 23,1968 3,364,848 CALENDER, ESPECIALLY FGR ?APER SA'llNIZlNG Ger-notMiiller, Krefeld, Germany, assignmto Job. Kleinewefers SohneMaschinenfahriir, Krefeld, Germany Filed Dec. 16, 1964, Ser. No. 418,824Claims priority, application Germany, Dec. 18, 1963, K 51,670 3 Claims.(Cl. 100-47) ABSTRACT OF THE DISQLUSURE Calender, especially forsatinizing paper in which a plurality of moveable rolls are arranged insuperposed relation above a stationary roll with a hydraulic unitconnected to each end of the uppermost roll, each unit having adownwardly acting larger surface and an upwardly acting smaller surface,and with fluid pressure means connected to said surfaces and with valvemeans being provided for exhausting the upper surface so that thehydraulic units can lift the rolls, or pressurizing both surfaces so therolls are urged downwardly into pressure engagement with each other.

The present invention relates to a calender, especially for satinizingpaper, and more specifically concerns hydraulic means used in connectiontherewith for exerting pressure on the calender rollers.

With satinizing calendars it is known to employ doubleacting fluidoperable cylinder piston systems for exerting pressure on the rollers toselectively press the rollers against each other or lift the same fromeach other.

Heretofore known arrangements of the type set forth above have thedrawback that with large and wide satinizing calenders, a low hydraulicpressure only is required for pressing the rollers against eachother--in view of the considerable weight of the pressing roller-while arather high hydraulic pressure is required to lift the pressing rolleroff the adjacent roller. Inasmuch as both pressures have to be furnishedby the same hydraulic unit, it was necessary heretofore, when exertingpressure upon the rollers, to reduce the pressure in the hydraulic unit.Aside from the fact that this brings about a loss in the pumping energy,it is particularly disadvantageous that a relatively long time isrequired to bring the pressure from the low pressure value up again tothe high pressure value for lifting the rollers from each other. Thisfact represents a considerable drawback, particularly when inserting apaper web, because, during such inserting operation, frequent shortsuccessive lifting and lowering operations with corresponding exertionof pressure have to be effected,

Another drawback of the heretofore known arrangements of theabove-mentioned type consists in that when exerting low pressure andalso when lifting the rollers from each other, due to the differentfriction in the guiding means for the bearings in the framework, therollers can no longer be lifted or lowered synchronously, and thepressure exerted upon the two roller ends will generally differ. This,in turn, may bring about tilting of the rollers and jamming.

Still another drawback of the above-mentioned heretofore knownarrangement consists in that it is not possible to exert differentpressures upon both calender sides, as is sometimes desirable inpractice.

It is, therefore, an object of the present invention to provide acalender, especially for satinizing paper, which will overcome theabove-mentioned drawbacks.

It is another object of this invention to provide a calender with ahydraulic lifting and lowering system in which the pressure furnished bythe pressure source remains substantially the same during lifting andlowering of the respective roller or rollers.

It is still another object of this invention to provide a calender withhydraulic lifting and lowering means, which will make it possible toexert different pressures on the two ends of a calender roller.

A further object of the invention consists in the provision of acalender as set forth in the preceding paragraphs, which willautomatically assure a synchronous movement of the ends of therespective calender roller.

These and other objects and advantages of the invention will appear moreclearly from the following specification in connection with theaccompanying drawing diagrammatically illustrating a calender accordingto the present invention.

A calender according to the present invention is characterized primarilyin that individual hydraulic cylinder piston means are respectivelyprovided for each calender side, while conduits and control means are soarranged and associated with said hydraulic cylinder piston means thateach hydraulic cylinder piston means can be eifective for that side ofthe calender only to which the respective hydraulic cylinder pistonsystem pertains.

Referring now to the drawing in detail, the calender illustrated thereincomprises a chilled cast roller 1, a plurality of elastic rollers 2 andchilled cast rollers 3 of considerably smaller diameter than roller 1.At both sides of the calender above the set of rollers l, 2. and 3 thereare respectively arranged two double-acting cylinder piston systems eachcomprising a cylinder 4, a piston 5 reciprocably mounted in cylinder 4,and a connecting rod 5 having its upper end connected to piston 5 andhaving its lower end connected to the bearing means 2 for the uppermostroller 2. As will be seen from the drawing, piston 2 is a double-actingpiston having a larger eifective top surface and a smaller effectivebottom surface. It will be appreciated that when pressure fluid isconveyed both to the top surface and the bottom surface of piston 5, thedifferential pressure acting on piston 5 will press the rollers 2, 3 and1 against each other. On the other hand, when pressure fluid acts uponthe bottom surface only of piston 5, connecting rod 5' will lift thevarious rollers off from each other. This lifting oif operation isefiected by a lifting spindle 6 in cooperation with adjusting nuts 7 and7'. More specifically, when piston 5 moves upwardly, an arm 2a of thebearing for the uppermost roller 2 engages a nut '7' threadedlyconnected to spindle 6 and thus lifts spindle 6 upwardly. After spindle6 has been lifted by a distance a, that nut on spindle 6 which isadjacent to the uppermost roller 3 engages arm 30: of the bearing meansfor said last-mentioned roller, so that any further lifting movement ofspindle 6 will lift said roller 3; Similar to the manner just described,all the other rollers will successively be picked up by the respectivenuts on spindle 6 so that the various rollers will be spaced from eachother. The nuts 7 are so adjusted that in the uppermost position ofpiston 5, substantially the same free gap will exist between alladjacent rollers.

When it is desired to have the various rollers in disengagement andspaced as just described for a longer period of time, spindle 6 may beprovided with additional nuts 9 spaced from each other, while a valve 8is adapted selectively to be actuated so as to have a plunger 8' thereofengage the space between the nuts 9 to thereby hold spindle 6 in itsuppermost position.

Nuts 7 are, of course, adjustable in conformity with the desiredspacing. As is evident from the drawing, while the left-hand side of thedrawing may represent the control arrangement for the left-hand side ofthe various rollers, the arrangement comprises a corresponding controlarrangement for the right-hand side of the rollers, as shown in thedrawing, and corresponding parts have been designated with the samereference numerals.

Hydraulic cylinder piston systems 4 are respectively hydraulicallyconnected with hydraulic fluid sources I and II for producing andstoring the respective desired hydraulic pressure. Each of saidhydraulic units comprises a pressure pump 16, a fluid pressure storingvessel 11, a pressure gauge 12 and a pressure fluid container 13. Aswill be evident from the drawing, pressure is conveyed to cylinder 4through pressure conduits 14 and 15 and a hydraulic reversing valve 23for the pressure above piston and a hydraulic reversing valve 21 for thepressure below piston 5.

When in conformity with the invention, the rollers are to be pressedagainst each other at a low pressure, both hydraulic units 20 and 21 aremade effective so that the difierential pressure corresponding to thecross-section of the piston rod will be eflective upon the rollers. Theadjustment for the maximum hydraulic pressure is effected by actuationof position indicators in contact gauges 12 which are adapted to switchon and off the pressure pumps 10.

Inasmuch as in case of a breakdown in the hydraulic units, especiallypressure conduits 18 and 19, it may occur that the pressure cylinderwill be subjected to full pressure only above piston 5 so that imprintsmay occur on the elastic rollers, there is, in conformity with thepresent invention provided a safety arrangement. This 7 safetyarrangement consists of an overflow conduit 22 with a check valve 24interposed between the cylinder chambers above and below pressure piston5. This check valve 24 is so designed that the pressure in the pressurechamber above piston 5 is adapted to equalize through a choke 25 withthe cylinder chamber below piston 5.

According to a further development of the present invention, thehydraulic units have associated therewith an electric, hydraulic, ormechanical synchronizing arrangement in order to prevent one calenderside from being litted or lowered faster than the other calender side inview of different conditions of friction, whereby a jamming of theroller'bearings may occur.

According to the drawing, the said synchronizing device is designed asan electro-hydraulic synchronizing device which comprises twopotentiometers 26 and 27 respectively connected to the bearin g means 2for both sides of the uppermost roller 2. In addition thereto, thesynchronizing device comprises a differential relay 28, which latter isadapted to open and close magnetic valves 29 and 36 provided in thepressure conduits 16 and 17 leading to the cylinder chambers abovepiston 5. The differential relay is connected to a slide contact 26a,27a cooperating with that part-of the potentiometer 26, 27 which isconnected to the bearing means for the uppermost roller.

From the above it will be evident that if one piston 5, for instance theleft-hand piston 5, moves downwardly at a somewhat higher speed than thepiston in cylinder 4 on the right-hand side, the current in theleft-hand coil of the differential relay will prevail whereby centralcontact member 28a which normally occupies an intermediate or zeroposition, will close valve 29 thereby somewhat retarding the transmittalof pressure until synchronization is established with the other cylinderand contact 28:: has returned to its intermediate or zero position.

When the roller set is lifted, it has heretofore been noted thatfollowing the frequent turning or machining of the rollers,unnecessarily large lifting movements are carried out when the pistons 5are permitted to move to their respective end position. In order toovercome this drawback, according to a further feature of thepresentinvention, the last-but-one roller (when looking downwardly) oneach side of the calender, has its bearing 2' provided with a preferablyadjustable contact 31 which by engagement with a contact member 33closes a circuit for a magnetic valve 31', 32 respectively when roller 2adjacent roller 1 has been spaced from the latter by the desireddistance, which means that the uppermost roller has reached its maximumheight. By closing the circuit for the magnetic valves 31, 32vthroughcontact 31, the valves, respectively interposed in pressure conduits 18and 19, are closed, so that no further lifting movement of pistons 5 andof the rollers can be effected. In other words, in this way anysuperfluous lifting operation will be eliminated regardless of therespective diameter of the rollers or other ground-off condition.

As will be evident from the foregoing description in connection with theaccompanying drawng, it is possible, in conformity with the presentinvention, by simultaneously subjecting both roller sets to pressure, topress the rollers against each other at a rather low pressure in spiteof the high pressure in the hydraulic units. This advantage is broughtabout by the fact that only the diflerential pressure in conformity withthe piston rod is effective for pressing the rollers against each other.On the other hand, the present invention makes it possible to adjust thefrequently necessary small pressure differences ,between the twocalender sides.

It is, of course, to be understood that the present invention is, by nomeans, limited to the particular construction shown in the drawings, butalso comprises any modifications within the scope of the appendedclaims.

What I claim is:

1. In a calender, especially for satinizing paper; a stationary roll anda plurality of moveable rolls arranged with their axes parallel and insuperposed relation, a hydraulic operating unit at each end of themoveable roll most remote from thestationary roll and connected to thesaid remote roll so as to move it in a direction toward the stationaryroll or in a direction away from the stationary roll, lost motionconnections between said moveable rolls whereby upon movement of saidremote roll in a direction away from said stationary roll the moveablerolls will all be moved into spaced relation to each other and to saidstationary roll, whereas upon movement of the remote roll toward saidstationary roll all the said rolls will interengage, each hydraulicoperating unit comprising a working piston connected to the remote rolland having a larger surface responsive to fluid pressure for moving theremote roll toward said stationary roll and also having a smallersurface opposed to said larger surface, substantially constant pressurefluid source means connected to each of said larger surfaces by arespective first conduit and to each of said smaller surfaces by arespective second conduit, a normally open electrically operable valve.in each of said first conduits, a differential switch havingopposedelectrical operators and operable to energize the electricallyoperable valve in one of said first conduits when a certain one of theelectrical operators becomes predominant over the other thereof, arheostat in circuit with each of said operators, means connected torespective ends of said remote roll for adjusting respective ones ofsaid rheostats as the remote roll is moved toward said stationary roll,and control means including valve means connecting said source meanswith the said larger and smaller surfaces of both of said hydraulicoperating units and operable for supplying fluid under pressure to bothof the said surfaces of each unit for pressing said rolls against eachother or for exhausting the larger surfaces of both of the units forcausing said rolls to be separated from each other. a v V 2. A calenderaccording to claim 1 in which said flui source means is connected toeach of said larger surfaces by a respective first conduit and to eachof said smaller surfaces by a respective second conduit, a normally openvalve in each of said second conduits, an electric actuator for each ofsaid valves, and means operable in responses to a predeterminedseparating movement of said rolls for energizing said actuators tointerrupt the said separating movement.

5 3. A calender according to claim 1 in which bypass channel means areprovided leading from each larger surface to the respective smallersurface and preventing fluid flow from the smaller surface to the largersurface while permitting fluid to flow slowly from the larger surface tothe smaller surface.

References Cited UNITED STATES PATENTS 2,058,352 10/1936 Putnam et a1.100162 X 2,267,380 12/1941 Tyler 6052 6 2,332,289 10/ 1943 Zeitlin1G0163 2,343,672 2/ 1944 Bench 100-46 2,545,921 3/1951 Goodwillie et all100168 X 5 FOREIGN PATENTS 523,866 4/ 1931 Germany.

665,489 9/1938 Germany.

270,054 11/1950 Switzerland.

10 LOUIS O. MAASSEL, Primary Examiner.

